A continuing demand for compactness exists in the information storage disk market. Earlier, this demand was satisfied by external rotor motors, which could be relatively short in an axial direction. Now that demand is also directed toward an ever-diminishing diameter of information storage disks and of the components whereupon the disks are positioned. At the same time, the motor must still supply adequate torque, have a certain minimum angular momentum and smooth-running operation, and inhibit the passage of dirt particles from its bearing assembly and/or torque-generating regions toward a “clean room” region, all without increasing its overall axial dimension. Additionally, always under focus is a need for cost reduction resulting in cheaper components such as the bearing assembly maintaining mechanical precision. In disk storage devices having a form factor of one inch and below for the storage medium diameter ball bearings especially cannot compete in regard to low noise generation and/or low manufacturing costs.